Optical-instrument drier



June 2, 1925. I 1,539,846

J.O.JANSSON OPTICAL INSTRUMENT DRIER Filed De. 29, 1925 mvENToR John O.Jansson BY n I K ATTORNEYS Patented June 2', 1925.

UNITED STATES PATENT OFFICE.

JOHN O. JANSSON, F HOBOKEN, NEW JERSEY, ASSIGNOR T0 KEUFFEL AIID ESSERCOMPANY, 0F HOBOKEN, NEW JERSEY, A CORPORATION 0F N'EW JERSEY.

OPTICAL-INSTRUMENT DRIER.

Application filed December 29, 1923. Serial N'o. 683,311.

To all whom z't may cof/wem.'

Be it known that I, JOHN O. JANssoN, a

citizen of the United States, and a resident of Hoboken, in the countyof Hudson and 5 State of New Jersey, have made land invented -certainnew and useful Improvements in Optical-Instrument Driers, of

which the following is a specification.

My invention relates to a novel method and apparatus for drying opticalinstruments and has for its object to provide a drier which Will besmall and compact in size and extremely light in weight, so as to beparticularly useful in the drying of periscopes of submarine boats,although it will be readily appreciated that the novel method andapparatus may be eiciently employed for the drying of other instruments.

In a great many optical instruments, such as, for example, gun sights,and particularly perisoopes, it is extremely important that the interiorof the instrument be free from moisture or dry, otherwise dew is liableto collect upon the inner surfaces of the lenses and by fogging the samewill prevent their proper use and function. It has been found that inactual service it is necessary to dry a periscope from time to time, andit has heretofore been necessary to either remove it from the boat andship it to the repair base or else provide each submarine boat with avacuum pump, but due to the very limited amount of available space in asubmarine boat this latter has been found to be objectionable andimpractical.

With my novel method and apparatus I am able to first create a vacuumwithin the interior of the instrument and then slowly enter so as tobring the pressure up to approximately atmospheric. By repeating thisprocess several times, I am able to entirely free the interior of theinstrument from moisture.

A further object of my invention is to provide a novel method of dryingand maintaining in a dry condition the interior of optical or otherinstruments by causing previously compressed and dried gas to create avacuum within the interior of the instrument and then allow the vacuumproducing as to pass over into the exhausted chamber of the instrument,and then by ysealing .the

allow a. sufficient fquantity of dry gas toV instrument insure that itwill remain in a dry condition.

A further object is to provide a novel apparatus for utilizing gas underpressure,

either from a tank or from a compressmn pump, by passing the samethrough an ejector and in so doing exhaust the periscope or otherinstrument to which the ejector is connected; and to further provide forthe closing of the instrument to the atmosphere and slowly allowing thegas under pressure to enter the exhausted chamber and thus prevent. anysudden change of pressure within the instrument which might tend todislodge or disrupt some of the more sensitive parts of the same.

A further object is to accomplish the aforementioned ends in a simpleand praetical manner, and with the foregoing and other objects in viewmy invention resides in the novel method of drying instruments and inthe novel apparatus employed. the combination and arrangement of partsthereof, and in the details of construct-ion, all of which will morefully hereinafter appear, it being understood that changes may be madewithin the scope of the appended claims without departing from thespirit of the invention. l

In the drawings accompanying and form-- ina part of this application:

igure 1 is a view in longitudinal section of my novel ejector apparatus;

Figure 2 is a fragmental view illustrating a somewhat different settingof the control valve thereof;

Figure 3 is a top plan view of the valve portion of the ejectorapparatus and particularly disclosing the dial inscriptions;

Figure 4 1s a view in section taken on the lline 4-4 of Figure 3; and

minates at its one extremity in the gas inlet pipe 14 and at its remoteextremity commumcates with the ejector nozzle proper 16. The duct 13terminates at its one extremity in the exhaust nozzle and at its remoteend communicates with the vacuum producing portion 17 of the ejectornozzle 16.

A transverse o ening 18 extends throughl i is further characterized bysuitable markin s'such as Vacuum at the point 27, low filling at thepoint 28, and Fast filling at the point 29. The periphery of the dial ispreferably provided with a notch 28', which, together with the springlatch member 30, acts las a suitable index arrangement and prevents thevalve from being acprovide the closing) cidentally turned past the slowfilling position. The spring latch member 30 also acts as an indicatorand when pointing to the several dial markings indicates the position ofthe valve. The body of the valve is further routed out to provide acurved slot A, which in conjunction with the pin B which is carried bythe dial plate limits the extreme positions of the valve.

The ducts 2O and 21 are so arrangedy that with the valve in the positionas indicated by the marking Vacuum the duct 2O will connect the ejectornozzle roper 16 with the` gas inlet pipe 14 and t e duct 21 will connectthe vacuum nozzle l5 with the vacuum producing pipe 17 of theY ejectorproper, this osition being illustrated in Figure 1. Wlth the dial turnedto th'e position indicated by Fast filling, the gas inlletnozzle 14 andvacuum nozz e 15 will both be closed to the atmosphere and will beconnected one to the other as disclosed in Figure 2. The intermediateposition. of the dial as indicated by the point Slow filling will of thenozzles 14 and 15 to the atmosphere ut will allow a very slow leakage ofgas from the inlet pipe over into the exhaust pipe 15.

In carrying out m novel method of drying instruments an in the actualuse of the apparatus described,` a tank 31, filled with compressed asand preferably nitrogen, is connected y a hose 32 to the inlet nozzle 14ofthe ejector. A second hose 33 is secured to the exhaust nozzle 15 andleads to an attaching fixture 34. The attaching lfixture includes apressure gauge 35 which is' adapted to register pressures both above andbelow atmospheric. The attaching fixture 34 also includes a threaded endmember 36 which when rotated b the thumb screw 37 is adapted vto engaget e threaded wall of an opening 38 which leads to the interior of theinstrument which is to be dried. A shut-ofi' plug 39 is adapted to closethe duct 38 after the vacuum drying and instrument filling has beenaccomplished.

lVith the parts as thus arranged, the valve is turned to the vacuumposition and the tank valve 40 is then opened. The rapid passing of thecompressed gas through the ejector causes a vacuum to be produced withinthe interior of the instrument. After a vacuum equal to approximately 22of' mercury has been obtalned, the valve of the ejector is turned untilthe index latch 30 snaps into the indexing notch 28,-.` and at whichposition the valveis held until the gas from the tank slowly filtersinto andreduces' the vacuum within the instrument,

thus preventing any sudden changes of pressure therein. After the vacuumhas been materially reduced the valve is furtherr turned until the fastfilling position is reached and a pressure of approximatel 10 lbs. persquare inch is allowed to build7 up wit-hin the instrument, thesepressures, however, are relative and may be varied as experience maydirect.

In most instances it will be advisable to repeat this process severaltimes in order to be sure that the instrument will be thoroughly andcompletely dry, after which the plug 39 is again returned to its placeand the instrument accordingly sealed. I have found that the bestresults are obtained when nitrogen gas is used, although it will bereadily appreciated that air from an air compressor could be substitutedfor the gas tank and fairly good results be obtained,- and in thisregard it is to be understood that the term gas refers to air as well asnitrogen, which latter is ordinarily used for the drying of instruments.

Having thus described and explained my invention, I claim and desire-tosecure by Letters Patent:

l. An apparatus for drying a closed rece tacle comprisin an ejector, thepressure si e of the ejector a a ted to communicate with a source of gasun er pressure, withI the vacuum side of the ejector adapted tocommunicate with the receptacle to be dried, and a valve associated withsaid ejector whereby the pressure side of the 4ejector and the Vacuumside thereof may be closed to the atmosphere and brought intocommunication one with the other.

2. A drying apparatus comprising an ejector includingA pressure andvacuum ducts extending therethrough, "a valve associated with saidlejector and provided .with two ducts communicating with thebducts of theejector and also adapted to close said ejector ducts to the atmosphereand to bring the pressure duct into communication with the vacuum duct.

3. A drying apparatus comprising an' ejector including pressure andvacuum ducts extending therethrough, a valve associated with saidejector and provided with two ducts communicating with the ducts of theejector and also adapted to close said ejector ducts to the atmosphereand to bring the pressure duct into communication with the vacuum duct,and means for indicating the position of the valve ducts and to arrestthe movement of the valve at the position of slow leakage from thepressure duct of the ejector intoithe vacuum duct. 1

4. A drying apparatus comprising a tank of compressed dry gas, andejector connected thereto and including pressure and vacuum ducts, thepressure duct communicating with said tank, the vacuum ductcommunicating with the chamber to be dried, a valve asso- 20 ciated withsaid ejector and ejector ducts and adapted to open the pressure duct tothe atmosphere and the vacuum duct to the vacuum-producing portion ofthe pressure duct to thereby allow the escapement of the dried gas tothe atmos here and cause a vacuum to be set up Wit in said chamberthereby, said valve further adapted to close said vacuum and pressureducts to the atmosphere and to provide a by-pass from said ressure ductto said vacuum duct to there y allow the dry compressed gas to pass fromthe said tank into said chamber and relieve the vacuum therein. Signedat Hoboken in the county of Hudson and State of New Jersey this 27th dayot'4 December, A. D. 1923.

JOHN O. JANSSON. Witnesses:`

SAMUEL Woon, Jr., CARL W. KEUTFEL.

